Primarily for an integrated semiconductor circuit with limited power supply, like e.g. for a usage in a battery-powered terminal equipment, it is desirable to spend a small electrical power dissipation for optimization of durability and extension of the operating time, respectively. Therefore, a so called stand-by mode is usually provided for such integrated semiconductor circuits in which essential parts and circuit areas of the integrated semiconductor circuit, respectively, are completely switched off or are operated at a reduced operating frequency, i.e. at an extended system clock. On demand, the integrated semiconductor circuit that has been put into the stand-by mode is switched over to an active mode at short notice.
Particularly for integrated semiconductor circuits that are operated for a long time or predominantly in the stand-by mode, the power consumption in this mode matters significantly. Provided that such a circuit is operated at a reduced operating frequency, the power consumption in the stand-by mode is principally dominated by leakage currents of individual switch- and storage elements (cells).